OsmAnd

This is a mapping application which allows you to use a map anywhere you need it without having a data connection. It also has online routing and audible navigation.

The application is open source and the offline data is based on OpenStreetMap - the free wiki map (OSM).

Highlights of the online mode:
- 14 different map layer sources from the Internet
- navigation (routing) with voice instructions
- search, edit POIs,
- submit OSM bugs.

Highlights of the offline mode:
- vector street map
- comprehensive search of addresses and places
- efficient storage format to fit big areas onto SD card

OsmAnd is still in active development. To support the project you can join the community, donate or co-fund a new feature which is important for you.
See web site for details.